This invention relates to the separation and isolation of oil sand aggregates into four components: 1) tars and pitches, 2) a kerosene fraction, 3) clays, silts (particle sizes of less than 80 xcexcm) and 4) sand (particles sizes of greater than 80 xcexcm).
It is known that oil sands can be separated and oil fractions isolated by one of many processes of which the ranked highest to lowest preference is the:
a) CHWE (Clark Hot Water Extraction Process) [1],
b) OSLO HWE (Oslo Hot Water Extraction Process) [2],
c) OSLO CWE (Oslo Cold Water Extraction Process) [2],
d) AOSTRAxe2x80x94Takiuk Process [3],
e) ZEFTE (Zero Fine Tailings Extraction Process) [4], and
f) BITMIN (Counter Current Desander Process) [5].
[1] FTFC (Fine Tailings Fundamentals Consortium) xe2x80x9cVol 4-29. Laboratory Experiments on the Clark Processxe2x80x9d In: Advances in Oil Sands Tailings Research, Alberta Department of Energy, Oil Sands and Research Division, Publisher.
[2] FTFC (Fine Tailings Fundamentals Consortium) xe2x80x9cVol 4-9. OSLO Hot and Cold Water Extraction Processesxe2x80x9d In: Advances in Oil Sands Tailings Research, Alberta Department of Energy, Oil Sands and Research Division, Publisher.
[3] FTFC (Fine Tailings Fundamentals Consortium) xe2x80x9cVol 4-6. AOSTRAxe2x80x94Takiuk Processxe2x80x9d In: Advances in Oil Sands Tailings Research, Alberta Department of Energy, Oil Sands and Research Division, Publisher.
[4] FTFC (Fine Tailings Fundamentals Consortium) xe2x80x9cVol 4-8. Zero Fine Tailings Extraction (ZEFTE)xe2x80x9d In: Advances in Oil Sands Tailings Research, Alberta Department of Energy, Oil Sands and Research Division, Publisher.
[5] FTFC (Fine Tailings Fundamentals Consortium) xe2x80x9cVol 4-8. BITMINxe2x80x9d In: Advances in Oil Sands Tailings Research, Alberta Department of Energy, Oil Sands and Research Division, Publisher.
This invention relates to the separation and isolation of resins and kerogens.
It is also known that resinous and wax like products can be separated from their host habitat by means of prolonged continuous Soxhlet extraction. The efficacy of extraction has been substantially increased by expanding the range of solvents used in analytical extraction tools such as Solid Phase Extraction (SPE) [6], Supercritical Fluid Extraction (SFE) [7], Pressure Fluid Extraction (PFE) [8], Accelerated Solvent Extraction (ASE) and Microwavexe2x80x94Accelerated Solvent Extraction (M-ASE) [9].
[6] Zief, M., Kieser, R., Solid Phase Extraction for Sample Preparation. Mallinckrodt Baker Inc. 1997.
[7] R. E. Majors LC/GC 17(6s) 8-13 (1999)
[8] Richter, B. E. LC/GC 17(6s) 22-28 (1999)
[9] Le Blanc, G., LC/GC 17(6s) 32-36 (1999)
To date, applications have involved micro analytical extraction of organic analytes from solid phases. One commercial application (known as the ALCELL PROCESS) involves the extraction of lignin from wood. A solvent mixture of methanol, ethanol and water at a pressure of 35 atmospheres is used to extract lignin from wood fiber[10].
[10] Lora, J. H. et al. U.S. Pat. No. 5,865,948
This invention, using thermal heating (preferably microwave), applies the micro analytical benefits of Accelerated Solvent Extraction to commercial applications. It extends the efficacy of the process of reduced extraction time, reduced solvent consumption and increased extraction efficiencies by introducing a temperature controllable biphasic solvent system i.e. a system that is the result of a mixture of an organic solvent and water which exhibits a Lower Critical Solution Temperature (LCST).
Some of the Inherent Problems Associated with Some or all of the Above Procceses (a-f) are:
Energy Usage
The processes require large net input of thermal and/or mechanical energy.[11]
[11] Strand, W. L.; Canadian Pat. 2 124 199 (1992 06 11)
Tailings and Storage Space
They also generate large quantities of tailings and require indefinite storage space. [11]
Bitumen Yields
Except for the AOSTRA-T Process, unacceptably low yields (54-92%) of bitumen are separable from the tar sands using present day technology. In fact, yields of 92-96% are considered to be high using the present art. [12]
[12] Sparks B. D., Majid A., Woods J.; Canadian Pat. 2 093 142 (1994 09 27)
In this invention yields of 99% are considered low from any and all of the ore bodies found in Alberta, Canada, the San Joaquin Valley of California and along the shores of the Orinoco River in Venezuela.
Hence, not only can more oil be squeezed out of less ore but utilization of the steps in our invention makes access to the lower grade ores economically viable.
Water Usage
Again, except for the AOSTRA-T Process in a-f above, large volumes of water are used in the extraction of bitumen. On average 0.7 to 3 MT of water are required per Metric Ton of ore (depending on the bitumen content of the ore). The lower the bitumen content the higher the volume of water required. Presently, in the case of the 12% bitumen content ore, 420,000 MT of water are required per day of full operation.[13]
[13] FTFC (Fine Tailings Fundamentals Consortium) xe2x80x9cVol. 2-3xe2x80x9d In: Advances in Oil Sands Tailings Research, Alberta Department of Energy, Oil Sands and Research Division, Publisher.
Environmental Concerns
Because the spent water presently generated contains toxic naphthenates, oil residues, and fine tailings, storage and containment of the waste waters has become an integral part of the process. The presently projected required volume of settling ponds doubles every 400 days. This is expected to decrease to 300 days when the Aurora mine comes on stream in the year 2004 i.e. 460,000,000 m3 per annum of new storage space for spent water shall be required.
It has been estimated that it will take 100-300 years for the colloidal of the fine tailings to agglomerate to a soft clay before release of the above mentioned waters shall be permitted to the environment. xe2x80x9cWithout further treatment of the existing fine tailings and without process modifications to reduce the rate of production of xe2x80x9cnewxe2x80x9d fine tailings, by the year 2030, over one billion cubic meters of a non-consolidating fine tailings would exist at the bottom of these lakes.xe2x80x9d . . . since xe2x80x9cContainment of the entire water system with the operating process is required as part of the operating license agreement between the Provincial Government and the two commercial plants.xe2x80x9d [14, 15]
[14]] FTFC (Fine Tailings Fundamentals Consortium) xe2x80x9cVol. 4-5.xe2x80x9d In: Advances in Oil Sands Tailings Research, Alberta Department of Energy, Oil Sands and Research Division, Publisher.
[15] Mac Kinnon, M. and Sethi, A.; A Comparison of the Physical and Chemical Properties of the Tailings Ponds at the Syncrude and Suncor Oil Sands Plants, Oil Sands_Our Petroleum future Conference, Edmonton, Alberta, Apr. 4-7, 1993.
AOSTRA Taciuk Process [16]
An advantage of the AT Process is that no toxic tailings are generated. Extra energy costs incurred by the process are partially offset by elimination of treatment and maintenance costs of the wastewater containment ponds. Although the process is self sufficient, the expended energy and specialty equipment must be costed against the process. Our process minimizes such cost while providing the opportunity to sell the energy to the open market.
[16] FTFC (Fine Tailings Fundamentals Consortium) xe2x80x9cVol. 4-10.xe2x80x9d In: Advances in Oil Sands Tailings Research, Alberta Department of Energy, Oil Sands and Research Division, Publisher.
Solid Phase Extraction Processes
Solid Phase Pressure Extractions have, to date, been limited to micro analytical applications. The ALCELL PROCESS has shown that high pressures can have economic restrictive effects on commercial applications.
The present invention provides a process whereby trapped and bound bitumen can be removed from an inorganic agglomerate of various size particles. Upon detachment and because of the ability of the solvent to physically set up a phase mixture system which has inherent density and solubility extremes, tars can be separated from oils and sand or diatomaceous earths can be separated from clays and silts.
Such solvent mixtures have the ability to separate into biphasic mixtures simply by adjusting the temperature of the solution or by changing its inorganic salt concentration.
The separating solvent solution is an aqueous mixture of lipophilic liquids that exhibit a Lower Critical Solution Temperature.
Some liquids exhibit total solubility over a range of concentrations and temperatures but partition into biphasic systems at specific concentrations and temperatures. They possess the specific ability to raise the lipophilic and hydrophilic characteristics of a solution by simple manipulation of the process variables. In other words, simple adjustment of the salt concentration or temperature greatly expands the separation abilities of the constituent solvents.
An example is Butoxy Ethanol in water. Solutions of greater than 10% and less than 57% Butoxy Ethanol will, below approximately 40xc2x0 C. remain in solution but partition into a biphasic system above 40xc2x0 C.
For example, 100 ml of totally miscible Butoxy Ethanol (density 0.90 g/ml) will, at 50xc2x0 C. give a biphasic system of 10 mls 57% Butoxy Ethanol in Water as a top phase (density 0.92 g/ml) and 90 mls of 10% Butoxy Ethanol in Water as a bottom phase (density 0.99 g/ml).
Such phenomena are known as Lower Critical Solution Temperatures. When the reverse phenomena is exhibited i.e. a biphasic mixture at a low temperature becomes a single phase at a higher temperature the solvents are said to have an Upper Critical Solution Temperature (UCST). Some mixtures do not exhibit an UCST at atmospheric pressure only because their boiling points are lower than their UCST""s. In order to exhibit an UCST it becomes imperative that the solvent solution be held under pressure while being heated.
The present invention provides a method of separating the organic from the inorganic phase in tar sands with a recyclable liquid composition whose LCST is above 40xc2x0 C comprising:
Sodium silicate . . . 0-2.5%
Sodium hydroxide . . . 0-2.5%
Alkyl or di alkyl glycol or di glycol ether and/or
Propyl glycol ether . . . Ingredient dependant
Triethyl amine and/or diethyl methyl and/or dimethyl pyridine and/or
methyl pyridyl and/or methyl piperidene . . . 0-10%
Water . . . to 100%
Pressure . . . 1-3 atmospheres depending on the Tg of the tars being extracted.
In preferred embodiments of the inventions the following proportions of components can be used. Sodium Hydroxide and/or Sodium Silicate 0-2.5%, preferably 0.5 to 2.5, particularly preferable 1-2%
All glycol ethers 0-100%, preferably 10 to 60 particularly 15-25%, especially 20%.